DE2025816B2 - HEAT-SENSITIVE COPY PADS - Google Patents

Description

The invention relates to heat sensitive copy sheets.

Numerous heat-sensitive copying sheets have been known, but these are becoming general those with a layer of two colorless solid compounds that are in contact with each other, to effect the conversion of color development, and with a thermally fusible material generally applied to a carrier. The staining mechanism of this heat-sensitive Copy sheets works in the following way:

When this sheet is placed on an original drawing and heated or with infrared rays is irradiated, preferably enhances the solid character image as part of the original drawing its temperature and the thermally fusible material of this part melts the two colorless compounds, and then the two melted compounds cause the reaction under color development. One of the two colorless compounds includes crystal violet lactones and benzoindolinone-spiro-pyrans, and the other includes, for example, clays such as acid clays, zeolite, kaolin, atapulgite and the like, mineral acids such as hydrochloric acid, sulfuric acid, Perchloric acid, phosphoric acid and the like, organic acids such as benzoic acid, p-chlorobenzoic acid, Bile acid, phthalic acid, salicylic acid, oxalic acid, maleic acid, citric acid, stearic acid and the like, and Phenols, such as p-butylphenol, p-phenylphenol, a-naphthol, Catechin, resorcinol and similar materials.

However, these heat-sensitive copying sheets show the defect that color developing fog is formed before heating, the stability of the developed color image such as lightfastness, Water resistance and the like, is poor and that the undeveloped sheets even Form colorations in the case where they are not heated and the like, since two compounds are formed on the Carriers are drawn in contact with each other, so that excellent heat-sensitive copying sheets continue to pose a problem.

The object of the invention is therefore to provide heat-sensitive copy sheets which do not form such color developing mist before heating, develop color on heating and the developed color image of which is excellent in light resistance and water resistance.

In the context of the invention it has been found that the above objects are achieved when a spiro compound represented by the following formula and an organic sulfonic acid are united, and this forms the basis of the invention.

The heat-sensitive copy sheets according to the invention comprise a spiro compound corresponding to the formula A, a solid organic sulfonic acid corresponding to the formula B and a heat-fusible material having a melting point from 50 to 180 ⁰ C and are at ordinary temperature of less than 5O ⁰ C on a support colorless:

wherein R ₁ and R ₂ each represent hydrogen atoms, alkyl groups with 1 to 8 carbon atoms, alkyl groups with 1 to 8 carbon atoms, carboxylic acid ester groups, aralkyl groups or phenyl groups,

R —SO ₃ H (B)

wherein R is an amino group, an N-substituted or unsubstituted aminoalkyl group with 2 to 18 carbon atoms, an alkyl group with 10 to 20 carbon atoms, an alkoxyl group with 10 to 20 carbon atoms, an alkyl group of 6 to 18 carbon atoms that reacts with a carboxylic acid is substituted, an aralkyl group or an aromatic ring.

The general method for making the heat-sensitive copy sheets according to the invention is dealt with below.

A nearly colorless spiro compound, an organic sulfonic acid and a thermally fusible one Material, as indicated above, are sufficient in a solution or suspension of a Binder mixed in an organic solvent or water and on a carrier such as paper or natural or synthetic resin films and the like, coated and dried. The above liquid mixture can be combed into the carrier. An opacifying agent can also be used when mixing added and mixed. The above procedure is not sensitive to heat Copy sheets limited according to the invention. For example, the above spiro compound and the thermally fusible material are mixed in a binder solution, and on the other hand the organic sulfonic acid and the thermally fusible material can be mixed in the binder solution and then both solutions can be mixed and drawn onto the support, or the former solution can be applied to the carrier and then the second solution drawn onto it will.

The amount of used to form the thermosensitive copy sheets of the invention Components is 1 to 2 parts by weight of the spiro compound corresponding to the formula A, 1 to 6 parts by weight of the organic sulfonic acid of the formula B, 3 to 30 parts by weight of the thermally fusible one Material, 3 to 15 parts by weight of the binder and 20 to 300 parts by weight of the solvent.

Examples of spiro compounds corresponding to formula A above are given below Table listed.

Color
development
middle R. J ν R ' Melting point Chemical name and literature
for the production I. H CH ₂ -CH ₂ - ^ \
/ s. H 258 "C 2,2'-spirobi- (benzo [f] chromene
J. Chem. Soc, 1927, 19 II CH ₃ H 203 ° C 3-methyl-2,2'-spirobi-
(benzo [f] -chrornen)
J. Pract. Chem. [2], 114,
190, Ber. 59, 1381 III CH (CHj) ₂ H 204 ° C 3-isopropyl-2,2'-spirobi-
(benzo [f] chrome)
J. Chem. Soc, 1929,942 IV C ₅ H ₁₁ H 182 ° C 3-amyl-2,2'-spirobi-
(benzo [f] chrome)
Ben, 61, 966 V QiH ₁₇ H 157 ° C 3-octyl-2,2'-spirobi-
(benzo [f] chrome)
J. Chem. Soc, 1929, 937 VI CH ₃ CH ₃ 238 C 3,3'-dimethyl-2,2'-spirobi-
(benzo [f] chrome)
Ber., 61, 967 VII COOC ₂ H ₅
j ν COOC ₂ H ₅ 205 to 207 ⁰ C 3,3'-dicarbethoxy
2,2'-spirobi- (benzo [f] -
chrome)
J. Chem. Soc, 1927, 1703 VIII H 207 ° C 3-benzyl-2,2'-spirobi-
(benzo [0-chrome)
Ber., 59, 1382 IX H 219 to 220 ° C 3- Phenäthy l-2,2'-spirobi-
(benzo [f] chrome)
J. Chem. Soc, 1931, 1336 X H 240 ° C 3-phenyl-2,2'-spirobi-
(benzo [f] -ch romen)
Ber., 59, 1383

These compounds are mostly in the form of colorless crystals.

These spiro compounds can be obtained by the condensation reaction of 2-hydroxy-1-naphthaldehyde with the respective corresponding ketones, as indicated in the literature above.

The organic sulfonic acids represented by the formula B can be exemplified by the following explained:

1. NH ₇ SO ₁ H

2. NH ₂ CH ₂ CH ₂ SO ₃ H

55

CH ₂ -CH ₂

3. N-O CH ₂ CH ₂ CH ₂ CH ₂ SO ₃ H

CH ₂ -CH ₂

-NHCH ₂ CH ₂ SO ₃ H

5. (CHj) ₂ NCH ₂ CH ₂ CH ₂ SO ₃ H

6. C ₁₀ H ₂₁ SO ₃ H

7. C ₂₀ H ₄₁ SO ₃ H

8. C ₁₂ H ₂₅ OSO ₃ H

9. C ₁₈ H ₃₇ OSO ₃ H

10. C ₁₆ H ₃₃ CHSO ₃ H

COOH

11. C ₆ H ₁₃ CHSO ₃ H

COOH

13. HO

CH ₂ SO ₃ H

Η, Ο — C

CH ₂ SO ₃ H

SO ₃ H

NH ₂

NH,

SO ₃ H

Cl

17. H ₂

18. Η ₂

Cl

Cl

19. CH ₃ COCH ₂ CONH -ζ V-SO ₃ H

/ V

NH- «f> -SO ₃ H

21. f \ —N — CH,

C, H _S

22. (C ₂ H ₅ ) ₂ N

/ V

SO ₃ H

SO ₃ H

C ₂ H ₅

23. H ₂ N ^ Q ^^ SOjH

Γ C ₂ H ₅

24. CHj - / ^^ SO ₃ H

NH ₂

25. Η ₂ Ν ^ ζ ^ —SO ₃ H

OC ₂ H ₅

26. CH ₇ CONH

SO ₁ H

CH,

SO ₃ H

32. Η, Ν

33

NH,

SO ₃ H SO ₃ H

SO ₃ H

34.

SO, H

NH,

35.

SO, H

36.

HO

37.

HO ₃ S

OH

SO ₃ H

HO

SO ₃ H

Cl OH

39.

HO, S

SO ₃ H

40. CH ₃ COHN

SO ₃ H

HO ₃ S

SO ₃ H

SO ₃ H

^OH

CH = CH

48. H ₂ N

CH = CH

SO ₃ H

y ~ v

NH,

SO ₃ H

SO ₃ H

NH

NH

CH = T

SO, H

OH

CH

NH

Ns

NH

N N

SO ₃ H

SO ₃ H

OH

SO ₃ H

SO, H

OH

SQ ₃ H

SO ₁ H

SO ₃ H

Examples of solvents which can be used in the context of the invention are organic solvents, such as Benzene, toluene, hexane, xylene, ligroin, acetone, ethyl acetate and similar materials, as well as water.

These solvents are used to dissolve the above binders or to emulsify the dispersion used and finally distilled off.

Albeit generally in the case of using organic sulfonic acids with an amino group of the formula B, if desired, an organic solvent or water can be used, results in the case of the use of organic sulfonic acids without amino groups or of those which are easily soluble in organic solvents, water the better results. In the case of application Organic sulfonic acids, which are easily soluble in water, will be the application of water enables. It seems to be caused by the fact that the one indicated by the formula A. Color former is not soluble in water. Examples of opacifying agents used in the context of In the invention can be used are titanium oxide, zinc oxide, barium sulfate, calcium sulfate, starch and similar materials.

The heat-sensitive copying sheets have the advantage that a color developing mist during during manufacture and during the period after drying and before heating

109 531/311

forms although the compounds of the formula A and B are in contact with one another, so that, even if the sheet is exposed before the copy color development, it has good stability in the course of the Has time without lowering the color developability and that when the copying is due The heat sensitivity in the copier takes place, the copied part the color within one Instantly developed and the developed color has good light resistance properties and water resistance properties having.

When phenols, such as. B. p-butylphenol, p-phenylphenol, «-Naphthol, catechin, resorcinol, 2,2'-methylene-bis- (4-chlorophenol), 4,4-Isopropylidenediphenol, and others in place of the compounds of Formula B are used, the sheet is not developed in color even when heated and is therefore not suitable for practice. When benzoic acid, p-chlorobenzoic acid, bile acid, phthalic acid, salicylic acid, Oxalic acid, maleic acid, citric acid, stearic acid and the like in place of the formula B reproduced compounds are used, the sheet does not develop in color even when heated, shows no difference in contrast and has poor light resistance properties and is therefore not suitable for practical use. Even if active tones, such as B. acid clays, zeolite, kaolin, atapulgite and the like, or mineral acids, such as. B. hydrochloric acid, sulfuric acid, perchloric acid, phosphoric acid and the like., Used the sheet shows the defect that there is color developing mist during mixing in the solvent and immediately after drawing on and drying.

If crystal violet lactone and benzoindolinone spiropyrane in place of the compounds accordingly formula A are used, the leaf develops a colored mist over the entire surface at the time of copy printing and has poor light resistance. It means that the combination of the reaction components as used according to the invention is unique Has an effect, as has been determined by numerous studies.

The following examples serve to further illustrate the invention.

example 1

35 g of the spiro compound I, 31 g of the organic sulfonic acid 17, 39 g of acetanilide, 120 g of a styrene-butadiene copolymer and 1200 g of toluene were mixed and ground in a ball mill for 2 days. The mixture solution was coated on paper and dried at 40 ⁰ C so that the heat-sensitive copying sheet was obtained. This sheet was superposed on an original drawing and heated by heat-sensitive copying in a machine (manufactured by Thermofax Secretary 3 M Co.) to obtain a blue-violet image. The copied image was exposed to sunlight for 20 hours. At this time, the part of the developed color image was not lowered in concentration as a whole, and the part of the undeveloped color image, that is, the non-image parts, were white as they were and were not changed, that is, the light resistance properties are excellent. Even when the sheet was left to stand under the conditions of a temperature of 50 ^° C. and a relative humidity of 80% for 20 hours, or even when it was wetted with water immediately after production, the concentration of the color-developed image was not lowered. This means that the water resistance is excellent.

On the other hand, a heat-sensitive copying sheet using crystal violet lactone has been made known coupler, bile acid as organic acid, acetanilide as thermally fusible material, of a styrene-butadiene copolymer as a binder and toluene as a solvent in the same manner as prepared above. The heat-sensitive copy sheet was prepared in the same manner as above heated and obtained a blue-violet image. The image faded and disappeared in the lightfastness test and water resistance test under the same conditions as above.

If 3-chlorosulfanilic acid (organic sulfonic acid 17) was substituted for the bile acid, were light resistance properties and water resistance properties equally bad.

Even if 1,3,3-trimethyl-8'-methoxy-indoline benzospiropyran as a known coupler and 4,4'-isopropylidenediphenol used as both an organic acid and a thermally fusible material were, the light resistance properties were poor, and even in the case of using the Organic sulfonic acid 17 together with this, the light resistance properties were poor.

B e i s ρ i e 1 2

35 g of the spiro compound II, 70 g of the organic sulfonic acid 57, 500 g / ^ - naphthol and 800 g of ligroin were mixed and milled in a ball mill for one day. Then 100 g of a styrene-butadiene copolymer and 800 g of toluene were added thereto and mixed for 2 hours and marry. The solution was drawn onto a film and dried at 40 ° C., whereby the heat-sensitive copy sheet was obtained. The sheet was placed on top of an original drawing and by means of a machine suitable for thermal copying (called Risofax, manufactured by Riso Kagaku Co., Ltd.) and a blue image obtained, which is similar to Example 1 was excellent in light resistance properties and water resistance.

Example 3

50 g of the spiro compound III, 300 g of urea and 600 g of acetone were mixed and placed in a ball mill ground for 2 days. Furthermore, 30 g of the organic sulfonic acid 8, 300 g of urea, 200 g of polybutyl methacrylate and 600 g of ethyl acetate are mixed and ground in a ball mill. the Ground materials were mixed and further ball milled for 5 hours. The treated mixture obtained was drawn onto a support and dried, while the photosensitive copy sheet obtained. The sheet was heated in the same manner as in Example 1 and get a blue picture. Lightfastness properties and waterfastness of the image were excellent in the same way as in Example 1.

Example 4

10 g of the spiro compound IV, 20 g of the organic sulfonic acid 36, 200 g of stearic acid, 70 g of a styrene

Maleic anhydride copolymers and 2000 g of xylene were treated in the same manner as in Example 1 and obtain a photosensitive copy sheet. The sheet was made in the same way as heated in Example 1 and obtained a blue image. If no organic sulfonic acid was used, no color was developed.

Example 5

10 g of the spiro compound V, 30 g of the organic sulfonic acid 49, 100 g of p-phenylphenol, 40 g of chlorinated Rubber and 3,000 g of benzene were treated in the same manner as in Example 1, and a heat sensitive one A copy sheet was obtained, which was then heated so that a blue image was obtained. If no organic sulfonic acid was used, no color was developed.

Example 6

10 g of the ground spiro compound VI and 100 g Acetanilide was dispersed in a solution of 30 g of polyvinyl alcohol and 500 g of water. Farther 10 g of the ground organic sulfonic acid 29 and 50 g of acetanilide were in a solution of 15 g Polyvinyl alcohol and 300 g of water dispersed. The two dispersions were mixed and used in one Treated ball mill for 5 hours, which was then drawn up on paper and dried so that the thermosensitive copying sheet was obtained which turned blue when heated Image revealed. If salicylic acid was used instead of organic sulfonic acid 29 (sulfosalicylic acid), no color was developed.

VII the color blue if the amount of organic sulfonic acid used is about 30 percent by weight was increased.

Claims (9)

Patent claims: 1. A thermosensitive copy sheet consisting of a support with an attached thereon Layer, the colorless, but in the melt reacting with each other to form color contains, characterized by (a) a spiro compound accordingly dc "r formula wherein R ₁ and R ₂ each represent hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, carboxylic acid ester groups, aralkyl groups or phenyl groups, (b) a solid organic sulfonic acid corresponding to the formula 35 40 Example 7 Example 1 was repeated using the spiro compounds VII, VIII, IX and X and thereby receiving blue images. Example 8 10 g of the spiro compound X, 15 g of the organic sulfonic acid 18, 140 g of benzoic acid, 50 g of a vinyl chloride-vinyl acetate copolymer and 1500 g of toluene were mixed and ground in a ball mill for 2 days, followed by drawing up on paper and dried, so that the heat-sensitive copying sheet was obtained. The sheet was on a Original drawing placed and heated by means of a machine suitable for thermal copying, whereby a blue image corresponding to the characters of the original drawing was obtained. Furthermore, the sheet was treated in the same manner as above, but with 50 g of hydroxyethyl cellulose and 1500 g of water in place of the vinyl chloride-vinyl acetate copolymer and toluene, with the same results. In any case, if an organic sulfonic acid was not used, a colored image could not be obtained will. Example 9 The color development of the respective combinations of the spiro compounds I to X and the organic Sulfonic acids 1 to 60 in the same manner as in Examples 1 to 8 made blue. However, in the In the case of using the coupler 1, the color becomes blue-violet and in the case of the use of the coupler R - SO ₃ H wherein R is an amino group, an N-substituted aminoalkyl group having 2 to 18 carbon atoms, an unsubstituted aminoalkyl group having 2 to 18 carbon atoms, an alkyl group having 10 to 20 carbon atoms, an alkoxy group having 10 to 20 carbon atoms, an alkyl group substituted with a carboxylic acid, the Alkyl group has 6 to 18 carbon atoms, or denotes an aromatic ring, and (c) a thermally fusible material with a melting point of 50 to 180 ^° C. 2. Heat-sensitive copy sheet according to claim 1, characterized in that the spiro compound the end 2,2'-spirobi- (benzo [f] -chromene), 3-methyl-2,2'-spirobi- (benzo [f] -chromene), 3-isopropyl-2,2'-spirobi- (benzo [f] -chromene), 3-amyl-2,2'-spirobi- (benzo [f] -chromene), 3-octyl-2,2'-spirobi- (benzo [f] -chromen), 3,3'-dimethyl-2,2'-spirobi- (benzo [f] - chrome),
3,3'-dicarbethoxy-2,2'-spirobi- (benzo [f] chromene), 3-benzyl-2,2'-spirobi- (benzo [f] -chromen), 3-phenethyl-2,2'-spirobi- (benzo [f] -chromen) or 3-phenyl-2,2'-spirobi- (benzo [f] chromene). 3. Heat-sensitive copy sheet according to claim 1, characterized in that the thermally fusible material made from acetanilide, urea, diphenylamine, diphenyl, naphthalene, benzoin, «-Naphthol, / ί-naphthol, p-tert.-butylphenol, ρ - phenylphenol, 4,4'- cyclohexylidene - diphenol, ^ '- isopropylidene diphenol, phthalic anhydride, Maleic anhydride, stearic acid, benzoic acid, naphthalene acetic acid, methyl p-hydroxybenzoate, Diphenyl phthalate, triphenyl phosphate or p-hydroxydiphenyl ether consists. 4. Heat-sensitive copy sheet according to claim 1, characterized in that the thermally fusible material at temperatures is practically colorless below 50 ⁰ C and the layer also contains a binder. 5. Heat-sensitive copy sheet according to claim 4, characterized in that the binder from a styrene-butadiene copolymer, an alkyd resin, a polybutyl methacrylate, a styrene maleic anhydride copolymer, a synthetic rubber, gum arabic, Polyvinyl alcohol or a hydroxyethyl cellulose consists. 6. Heat-sensitive copy sheet according to claim 1, characterized in that the spiro compound, the sulfonic acid and the fusible material are contained in the carrier. 7. Heat sensitive copy sheets, consisting of a combination of two supports, wherein a carrier a coating of a layer which (a) a spiro compound corresponding to the formula A, and (b) contains a solid organic sulfonic acid of the formula B as the second reaction component, and the other carrier is a coating of a layer that is a thermally fusible one Contains material with a melting point of 50 to 180 ⁰ C, has. 8. Heat sensitive copy sheets, consisting of a combination of two supports, wherein a carrier has a coating thereon of a layer which (a) corresponds to a spiro compound of formula A and (b) contains a thermally fusible material having a melting point of 50 to 180 ° C, and the other Support a coating of a layer containing a solid organic sulfonic acid corresponding to the formula B contains. 9. Heat-sensitive copy sheets, consisting of a combination of two supports, one surface having a coating thereon of a layer which contains a spiro compound corresponding to the formula A, and the other surface having a coating thereon which is a layer which (a) a solid organic Sulphonic acid corresponding to the formula B and (b) contains a thermally fusible material with a melting point of 50 to 180 ^° C.